Random results with Apache Solr and Drupal
The schema.xml that comes with the Drupal Apache Solr module doesn't define the random_* field compared to the default xml included in the apachesolr package. We needed that functionality for a project where we wanted to display 3 blocks which showed random results based on a couple of fields available in the node, in our case the author, title and a cck field. With 300k nodes, a random result was giving a nicer experience instead of seeing the same results coming back over and over. Adding random order is pretty easy in a few simple steps: http://lucene.apache.org/solr/api/org/apache/solr/schema/RandomSortField.html Implementing the tags from that manual did not have a lot of success, however, after some fiddling, following changes in the xml seem to do the trick. Feel free to add comments and suggestions.
<!-- goes in types -->
<fieldtype class="solr.RandomSortField" indexed="true" name="rand">
<!-- goes in fields -->
<dynamicfield indexed="true" name="random*" stored="true" type="rand"> </dynamicfield>
</fieldtype>After indexing your nodes, try to run following query on your solr admin page:
http://localhost:port/solr/select?q=whatever&morekeyshere&sort=random_127789 desc Our blocks are defined via hook_block which uses the apachesolr_search_execute() function to launch our query to the solr engine. With the hook_apachesolr_modify_query you can add a sort parameter and you'll get your random results.
<?php
function hook_apachesolr_modify_query(&$query, &$params, $caller) {
if ($caller == 'whatever') {
$seed = rand(1, 200);
$params['qt'] = 'standard';
$params['sort'] = 'random_'. $seed .' asc';
}
}
?>
Comments
Robert Douglass on Sun, 20/12/2009 - 12:59
As of RC4 there's a random field in the schema. It's not used anywhere in the module yet, but your techniques here can now be used without having to modify schema.xml.
<!-- A random sort field -->
<dynamicField name="random_*" type="rand" indexed="true" stored="true"/>
joetsuihk on Tue, 21/12/2010 - 03:50
"http://localhost:port/solr/select?q=whatever&morekeyshere&sort=random_1… desc" do not work on 6.x-2.0-beta3
seems param name "sort" is not used anymore, "solrsort" instead, but "http://localhost:port/search/apachesolr_search/whatever&solrsort=random… desc" do not work either.
riddhi on Tue, 14/02/2012 - 10:06
I want to get random result on the basis of CCK field i.e. On the basis of membership, there are 3 types and I want to get random and sorted result on membership. Pls confirm what steps we need to do for a particular cck field?
Linda on Sat, 28/12/2013 - 03:44
I'm not quite sure if the above applies to my situation.
I would like to execute a search using the Apache Solr Search module that based on a randomly selected taxonomy term field.
I'm using Drupal 7 so assuming I should be using hook_apachesolr_query_alter.
Any input would be appreciated.
Thanks,
Linda
swentel on Sat, 28/12/2013 - 12:40
That hook is the right one. You'll have to todo something like this
<?php
$query->addFilter('name_of_the_solr_key', $term_id);
?>
You can find the names of those keys in the administration overview of solr itself.
Add reply